1, meaning different, normally open fire doors are always open, and will be automatically closed by the control system only in case of fire. Generally used in public places or corridors. Normally closed fire doors are closed under normal circumstances and in case of fire. People need to push them open when walking, which plays the role of smoke prevention and fire prevention and prevents the fire from spreading.
2. With different prices, it is more expensive and more systematic to always open fire doors. Normally closed fire doors are relatively low in price.
3. The composition is different. Normally-open fire doors are composed of door leaves, door frames, door closers, sealing strips, release switches and other components. Normally-closed fire doors are equipped with sequencers in addition to the above components.
4. Different control methods. The normally open fire door is controlled by the fire door release switch, and the normally closed fire door does not need to be equipped with electrical automatic control. Door closers and sequencers are mainly used to close doors, that is, mechanically.
Extended data
Precautionary measures for fire doors
1, the installation of fire doors should be based on the types of fire doors used, and appropriate installation methods should be adopted.
2. The door frame of the fire door can be fixed with the wall by expansion bolts, or iron pieces can be embedded in the hole when building the wall, and welded with the door frame connector when installing.
3. No matter what connection method is adopted between the door frame and the wall, there should be no less than 3 anchor points on each side, and they should be firmly connected.
4, when installing fire doors, should first find straight, hanging, temporary fixed after appropriate size, and correction, adjustment, and correct the rear can connect and anchor.
5. It is required that the sliding door can be pushed and pulled flexibly after installation; Horizontal doors are easy to open and close.
6. Door closers must be installed on fire doors, and sequencers should be installed on opposite doors.
7, handle on the fire door, fire lock and other hardware accessories, must be complete.
8. The clearance with the ground plane is not more than 5 mm ..
References:
Baidu encyclopedia-fire door